Leadframe package with recessed cavity for LED

ABSTRACT

An LED package includes a die pad having a bottom surface, an upper surface and a centrally located recessed cavity. The recessed cavity has a chip attach surface between the bottom surface and upper surface and sidewalls that extend from the recessed chip attach surface to the upper surface. The package additionally has leads arranged on opposing sides of the die pad. The leads have a bottom surface that is coextensive with the bottom surface of the die pad and an upper surface coextensive with the upper surface of the die pad. An LED chip is attached to the chip attach surface. The package further includes a package body having an encapsulant which fills space between the die pad and leads forming a bottom encapsulant surface that is coextensive with the bottom surfaces of the die pad and leads.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Malaysian Patent ApplicationNo. PI 2010005176, filed Nov. 2, 2010, the entire contents of which areincorporated herein by reference for all purposes.

BACKGROUND

The present invention relates generally to integrated circuit (IC)packaging technology. More particularly, embodiments of the presentinvention pertain to leadframe packages with recessed cavities for lightemitting diodes (LEDs).

Leadframes are commonly used to package ICs. One example of a knownleadframe IC packaging technique is shown in FIG. 1. FIG. 1 is asimplified cross-sectional view of a conventional molded leadframepackage (MLP) 10. MLP 10 includes an IC die 12 attached to a die pad 14(also referred to as a die paddle) of a leadframe by an adhesive 13.Bonding pads 18 on top of IC die 12 are connected to leads 16 of theleadframe by wirebonds 19. An encapsulant material 20 covers the packageincluding IC die 12, wirebonds 19, and upper surfaces of die pad 14 andleads 16. Die pad 14 and leads 16 are exposed on the bottom tofacilitate heat dissipation from IC die 12 and to decrease overallthickness of MLP 10. Half-etched portions 17 of the leadframe are formedon sidewall surfaces of die pad 14 and leads 16. Encapsulant material 20extends underneath half-etched portion 17 to mechanically secure die pad14 and leads 16 to MLP 10.

MLP 10 is typically one of many IC packages that are formed in a matrixpattern using a leadframe strip. FIG. 2 is a simplified plan view of aconventional leadframe strip 30 that can be used to form a plurality ofleadframe packages. Leadframe strip 30 includes an outer frame 32 towhich a number of horizontal and vertical connecting bars 36, 38 areattached. Horizontal and vertical connecting bars 36, 38 define aplurality of inner frames 40 arranged in a matrix that each include anIC receiving area (or die pad). In this example, leadframe strip 30includes a matrix of 9×9 inner frames 40. Outer frame 32 includes aplurality of positioning holes 34 that can be used to position leadframestrip 30 on appropriate tools during die attach, wirebonding,encapsulation, and singulation processes.

FIG. 3 is an enlarged view of a portion of a leadframe strip. FIG. 3shows the portion of leadframe strip 30 inside dashed box A of FIG. 2.FIG. 3 shows a die pad 14 and leads 16 within each inner frame 40.

Some LED assembly processes use leadframes similar to the leadframeshown in FIGS. 1 and 3 and that may include die pads, leads, half-etchedportions, and encapsulant materials. One example is shown in FIG. 4,where an LED die 42 is positioned directly on top of a die pad 44 andthen placed under a dome 45 (or lens) that forms a cavity around LED die42. There are certain limitations associated with such LED packagingtechniques. For example, luminescence efficiency may be low due to lightthat is dispersed sideways and/or imprecise alignment between LED die 42and dome 45.

There are also manufacturing limitations associated with current LEDpackaging techniques. For example, current LED packaging techniquesgenerally suffer from low productivity due to low density leadframesand/or substrates, low production rates (number of units produced perhour), high capital investments, long lead times for new tooling andqualification, and other limitations.

In light of the above and in view of a general trend of shorter producelife cycles for LEDs, improved LED packages and manufacturing methodsare desired.

SUMMARY

Embodiments of the present invention provide a LED leadframe packagehaving a recessed cavity in a top surface of a die pad. An LED die canbe positioned within the recessed cavity, and sidewalls of the recessedcavity can function as reflectors for light emitted from the LED die.Further, an angle of the sidewalls can be selected to provide a desiredbeam profile for the light emitted from the LED die (e.g., focused,straight, or wide-angle).

In an embodiment of the present invention, an LED package is providedthat includes a die pad having a bottom planar surface, an uppersurface, and a centrally located recessed cavity. The recessed cavityhas a chip attach surface between the bottom planar surface and theupper surface. The recessed cavity also has sidewalls that extend fromthe recessed chip attach surface to the upper surface. The packageadditionally has first and second leads arranged on opposing sides ofthe die pad. The first and second leads have a bottom planar surfacethat is coextensive with the bottom planar surface of the die pad and anupper planar surface that is coextensive with the upper surface of thedie pad. An LED chip is attached to the chip attach surface within therecessed cavity. The LED chip has first and second bonding pads locatedon an upper surface thereof. The first and second bonding pads areelectrically connected to the first and second leads by first and secondconductors respectively. The package further includes a package bodyhaving an encapsulant, wherein the encapsulant fills space between thedie pad and first and second leads forming a bottom encapsulant surfacethat is coextensive with the bottom planar surface of the die pad andthe bottom planar surface of the first and second leads.

In another embodiment, a plurality of LED chips are attached to the chipattach surface of the recessed cavity of the die pad. Each of the LEDchips has first and second bonding pads located on an upper surface ofthe chip. A plurality of sets of first and second leads are arranged onopposing sides of the die pad. One set of first and second leads areprovided for each of the LED chips in the plurality of chips such thateach set the first and second bonding pads are electrically connected toeach set of the first and second leads by each set of first and secondconductors respectively.

In another embodiment of the present invention, a leadframe for use inmaking LED packages is provided. The leadframe includes a rectangularouter frame having an upper planar surface and a lower planar surface.The leadframe additionally includes a plurality of inner frames arrangedin a matrix pattern within the outer frame. Each of the inner frames hasa chip containing area and first and second leads arranged on opposingsides of the chip containing area. The chip containing area and firstand second leads have a bottom surface coextensive with the lower planarsurface and have an upper surface coextensive with the upper planarsurface. The chip containing area further includes a centrally locatedrecessed cavity having a recessed planar surface between the upper andlower planar surfaces of the leadframe and having sidewalls that extendfrom the recessed planar surface to the upper surface.

In yet another embodiment, a method of manufacturing an LED package isprovided. The method includes mounting a large panel frame/substrate(LPF/S) having a substantially square shape to a ring. The LPF/Sincludes a plurality of die pads and a corresponding plurality of leadsarranged in a matrix pattern. Each of the die pads includes a planarchip attach surface. An LED chip is attached to the planar chip attachsurface of each of the die pads. An encapsulant material is appliedoverlaying the LED chips and at least a part of the LPF/S. Each die padand corresponding leads are separated from the LPF/S to form individualLED packages. The steps of attaching the LED chips and applying theencapsulant material are performed while the LPF/S is mounted to thetaped ring.

In some embodiments, applying the encapsulant material further includesproviding an array mold cavity, dispensing the encapsulant material intothe array mold cavity, engaging the array mold cavity including theencapsulant material with the LPF/S including the LED chips, and curingthe encapsulant material.

Many benefits are achieved by way of the present invention overconventional techniques. For example, some embodiments include a singlepiece die pad with a recessed cavity where an LED chip can be attached.Sidewalls of the recessed cavity can be used to reflect light emittedfrom the LED chip. Using a single piece die pad with a recessed cavitycan simplify the LED packaging process because additional steps forforming reflective surfaces are not required. As another example, someembodiments utilize light reflectors that can be inserted within therecessed cavity. The light reflectors can be used to modify lightemitting properties of the LED package without requiring changes to theleadframe. Thus, embodiments of the present invention can provide LEDpackages with various luminescence patterns and efficiencies whilereducing manufacturing complexity and shortening manufacturingleadtimes. Depending upon the embodiment, one or more of these benefitsmay exist. These and other benefits are described throughout thespecification and more particularly below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified cross-sectional view of a conventional moldedleadframe package;

FIG. 2 is a simplified plan view of a conventional leadframe strip thatcan be used to form a plurality of leadframe packages;

FIG. 3 is an enlarged view of a portion of a leadframe strip;

FIG. 4 is a simplified cross-sectional view of a conventional pre-moldedtype package for housing an LED;

FIG. 5 is a simplified cross-sectional view of an LED package accordingto an embodiment of the present invention;

FIG. 6 is a simplified diagram of exemplary light reflectors and insertsaccording to an embodiment of the present invention;

FIG. 7 is a simplified diagram of different light beam profiles producedby LED packages formed in accordance with an embodiment of the presentinvention;

FIG. 8 is a simplified cross-sectional view of an LED package havingexternal I/O interconnects and an external heat sink in accordance withan embodiment of the present invention;

FIGS. 9A-9B are simplified plan views of LED packages according toembodiments of the present invention;

FIGS. 10A-10B are simplified plan views of a large panel frame/substratethat may be used in making LED packages according to an embodiment ofthe present invention;

FIG. 11 is a flowchart illustrating an exemplary process of assembling amolded LED package according to an embodiment of the present invention;

FIG. 12 is a simplified diagram of a large panel frame/substrate mountedon a taped ring for processing according to an embodiment of the presentinvention;

FIGS. 13A-13B are simplified cross-sectional views illustrating amolding process in assembly of an LED leadframe package according to anembodiment of the present invention; and

FIGS. 14A-14B are simplified cross-sectional views illustrating amolding process in assembly of an LED leadframe package according toanother embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention provide a LED leadframe packagehaving a recessed cavity in a top surface of a die pad. An LED die canbe positioned within the recessed cavity, and sidewalls of the recessedcavity can function as reflectors for light emitted from the LED die. Inan embodiment, the sidewalls can be coated with a glossy or matte finishto modify reflectivity of the sidewalls. In another embodiment, a lightreflector can be inserted within the recessed cavity. In each of theseembodiments, a shape of the recessed cavity can vary from circular,square, hexagonal, etc. Further, an angle of the sidewalls can beselected to provide a desired beam profile for the light emitted fromthe LED die (e.g., focused, straight, or wide-angle).

FIG. 5 is a simplified cross-sectional view of an LED package 500according to an embodiment of the present invention. This diagram ismerely an example that should not unduly limit the scope of the claims.One of ordinary skill in the art would recognize many variations,alternatives, and modifications. LED package 500 includes a die pad 502having an upper surface 504 and a bottom planar surface 506. LED package500 further includes leads 508, 510 arranged on opposite sides of diepad 502. Die pad 502 and leads 508, 510 are typically made of aconductive material such as metal. Electrically conducting wires, suchas wire 512, connect each of the leads 508, 510 to a bonding pad, suchas bonding pad 514, located on an LED chip 518. Leads 508, 510 have abottom planar surface 518 that is coextensive with bottom planar surface506 of die pad 502. Bottom planar surface 506 of die pad 502 may beexposed to an ambient surrounding or attached to an external heat slugto enhance dissipation of heat generated by LED chip 518. Leads 508, 510also have an upper planar surface 520 that is coextensive with uppersurface 504 of die pad 502. Further, leads 508, 510 have an upper innersidewall surface 522 facing die pad 502 that extends from upper surface520 to a lower edge between upper surface 520 and bottom planar surface518. Leads 508, 510 also have a lower inner sidewall surface 524 facingdie pad 502 that intersects with bottom planar surface 518 and anintermediate surface that extends from the lower edge of upper innersidewall surface 522 to lower inner sidewall surface 524.

An encapsulant material 526 covers upper planar surface 504 of die pad502 and upper planar surface 520 of leads 508, 510. Encapsulant material526 also at least partially covers lower inner sidewall surface 524 andupper inner sidewall surface 522 of leads 508, 510. Encapsulant material526 fills recessed cavity 528 to cover LED chip 518 and form part of LEDpackage 500. Encapsulant material 526 also fills spaces between theleads 508, 510 and the die pad 502 wherein a bottom surface ofencapsulant material 526 is coextensive with bottom planar surface 518of leads 508, 510 and with bottom planar surface 506 of die pad 502. Inan embodiment, encapsulant material 526 forms a lens and a package lid.

A chip attach surface extends along a bottom of recessed cavity 528 andsidewalls extend from the bottom of recessed cavity 528 to upper planarsurface 504 of die pad 502. LED chip 518 is attached to the chip attachsurface by an adhesive. The sidewalls of recessed cavity 528 may beformed in any particular shape (e.g., circular, rectangular, hexagonal,etc.) depending on the particular application. In one embodiment, thesidewalls of the recessed cavity 520 are coated with a glossy or mattefinish to modify reflectivity of the sidewalls.

In some embodiments, a light reflector may be inserted into recessedcavity 528 to reflect light emitted from LED chip 518. FIG. 6 is asimplified diagram of exemplary light reflectors and inserts accordingto an embodiment of the present invention. As shown in FIG. 6, the lightreflectors may be formed in various shapes and profiles includingcircular, rectangular, octagonal, etc. The different shapes may be usedto modify properties of the reflected light beam from LED chip 518.Similar to recessed cavity 528, sidewalls of the light reflectors canhave a glossy or matte finish depending on the particular application.The sidewalls may also be plated with a plating material or may be of aparticular color to enhance reflective properties of the sidewalls.

In an embodiment, a shape of a portion of the light reflector that fitsinto recessed cavity 528 may be standardized. This way, a standardizeddie pad 502 and recessed cavity 528 can be used with light reflectorshaving sidewalls of any shape.

FIG. 7 is a simplified diagram of different light beam profiles producedby LED packages formed in accordance with an embodiment of the presentinvention. The different profiles can be produced by modifying an angleof the sidewalls in the recessed cavity and/or an angle of the sidewallsof a light reflector. As shown in FIG. 7, light beams having focusedprofiles, straight profiles, or wide-angle profiles can be produced.Additionally, the sidewalls may have a bend with multiple angles or becurved depending on the desired light beam profile.

FIG. 8 is a simplified cross-sectional view of an LED package 800 havingexternal I/O interconnects 811, 813 and an external heat sink 815 inaccordance with an embodiment of the present invention. External I/Ointerconnects 811, 813 may be used to connect leads 808, 810,respectively, to a circuit board 817 as shown in FIG. 8. External I/Ointerconnects 811, 813 may be formed using any conductive material(e.g., solder). In some embodiments, an external heat slug 815 may becoupled to a bottom of die pad 802 to increase heat dissipation from anLED chip 818. External heat slug 815 may be formed using any materialhaving good heat conductivity (e.g., aluminum). Heat dissipation mayalso be increased by increasing a thickness of die pad 802. In anembodiment, for example, a thickness of die pad 802 is increased tobetween about 12-20 mil compared to a standard thickness of betweenabout 6-8 mil. An external heat slug and/or a die pad having anincreased thickness may be used to lower a temperature of packagescontaining high power LEDs.

FIGS. 9A-9B are simplified plan views of LED packages according toembodiments of the present invention. FIG. 9A shows a LED package 900having a single LED chip 910 attached to a die pad 902. As explainedabove with regard to FIG. 5, LED chip 910 may be disposed on a chipattach surface 904 that extends along a bottom surface of a recessedcavity. Leads 906, 908 are disposed on opposing sides of die pad 902,and bonding wires electrically connect leads 906, 908 to respectivebonding pads on LED chip 910. Additional leads may be disposed on a topand bottom of die pad 902.

As would be appreciated by one of ordinary skill in the art, increasinga number of LED chips in an LED package can increase illumination and/orprovide for a broader spectrum of emitted light. Accordingly, FIG. 9Bshows a LED package 912 having a plurality of LED chips 922, 924, 926,928 attached to a die pad 914. LED chips 922, 924, 926, 928 are disposedon a chip attach surface 916 that extends along a bottom surface of arecessed cavity. A plurality of leads 918, 920 are disposed on opposingsides of die pad 914, and bonding wires electrically connect theplurality of leads 918, 920 to respective bonding pads on LED chips 922,924, 926, 928. Additional leads may be disposed on a top and bottom ofdie pad 914. Although LED package 912 includes four LED chips in thisexample, any number of LED chips may be used in an LED package inaccordance with embodiments of the invention.

FIGS. 10A-10B are simplified plan views of a large panel frame/substrate(LPF/S) 1000 that may be used in making LED packages according to anembodiment of the present invention. As shown in FIG. 10A, LPF/S 1000has a rectangular outer frame 1002. In an embodiment, outer frame 1002has a size of 178 mm×178 mm. As would be appreciated by one of ordinaryskill in the art, outer frame 1002 may be larger or smaller depending onthe particular application. A plurality of inner frames are arranged ina matrix pattern within outer frame 1002. FIG. 10B is an enlarged viewof a portion of LPF/S 1000 showing some of the inner frames. As shown inFIG. 10B, the plurality of inner frames are attached to horizontal andvertical connecting bars 1006, 1008. Each of the inner frames includes achip attach surface 1004 extending along a bottom of a recessed cavity.An LED chip may be attached to the chip attach surface 1004 in each ofthe inner frames. Each of the inner frames also include leads 1010arranged on opposing sides of the chip attach surface 1004. As explainedabove with regard to FIG. 6, a light reflector 1012 may be inserted intothe recessed cavity of each frame.

FIG. 11 is a flowchart illustrating an exemplary process of assembling amolded LED package according to an embodiment of the present invention.Some embodiments of the invention provide increased packaging efficiencyby using a LPF/S that is larger than conventional leadframes. As anexample, a LPF/S having a size of up to 178 mm×178 mm or larger may beused in some embodiments. This is compared with conventional leadframesthat may have a size of about 40 mm×140 mm. These features allow anextremely high density that is not possible with a conventional LEDpackaging techniques. The increased packaging efficiency gained by usingthe LPF/S can reduce assembly costs. As described more fully below, theLPF/S may be mounted to a carrier or ring to support the LPF/S duringthe assembly process. Further, the LPF/S may be transported duringassembly processes using a handler that provides precise movement inboth “X” and “Y” directions (e.g., forward/backward and lateraldirections).

Steps 1102-1108 of FIG. 11 are typically considered part of a front ofline (FOL) phase, and steps 1110-1112 are typically considered part ofan end of line (EOL) phase. At step 1102, a LPF/S is mounted to a ringand offloaded to a slot film frame cassette. The ring provides supportfor the LPF/S and enables precise movement during the assembly process.In an embodiment, the ring is a metal support made from aluminum orstainless steel. The LPF/S may be mounted to the ring using, forexample, an adhesive high temperature tape that can withstandtemperatures that may exceed 200° C. during wirebonding and moldingsteps. As shown in FIG. 12, an LPF/S mounted to a circular-shaped ringcan be transported in both “X” and “Y” directions during the assemblyprocess. In step 1104, LED chips or die are attached within recessedcavities of die pads on the LPF/S. In an embodiment, the LED chips maybe attached using an adhesive. The LED chips are typically placed ontothe die pads using a pick and place method. Movement of the ring in boththe “X” and “Y” directions enables precise placement of the LED chipswithin the recessed cavities of the die pads. In step 1106, the adhesiveused to attached the LED chips is cured. In an embodiment, the cure mayinclude a thermal treatment at temperatures of between 100° C. to 200°C. for between 1 hour to 3 hours. In step 1108, a wirebonding process isused to electrically connect leads on the LPF/S to respective bondingpads on the LED chips using bonding wires. In some embodiments, theassembly process may also include dispensing phosphor over the LED chipsto enhance or change a color of lighted emitted from the LEDs. Someembodiments may also include one or more cleaning steps that may includea plasma process in accordance with known techniques.

The EOL phase includes a molding process at step 1110. In an embodiment,the molding process includes dispensing an encapsulant material in anarray mold cavity and submerging the LPF/S and attached LED chips in theencapsulant material. This can be shown with reference to FIGS. 13A-13Band 14A-14B, which illustrate exemplary molding processes for formingLED packages. As illustrated in FIG. 13A, an encapsulant material, suchas a silicone hybrid compound, may be injected in an array mold cavityusing a dispense nozzle. The array mold cavity is then engaged with theLPF/S and the encapsulant material is cured to form an array of LEDpackages. The array of LED packages are separated at step 1112 using asingulation process to provide a plurality of LED packages. An exemplaryLED package formed using the array mold cavity of FIG. 13A isillustrated in FIG. 13B. FIGS. 14A-14B provide examples of LED packageshaving a “dome” shape that may be formed by changing the array moldcavity illustrated in FIG. 14A. Array mold cavities having other designsmay be used with in accordance with embodiments of the invention. Theabove molding processes are in contrast to conventional techniques thatuse individual as opposed to array mold cavities.

It should be appreciated that the specific steps illustrated in FIG. 11provide a particular method in accordance with an embodiment of thepresent invention. Other sequences of steps may be performed accordingto alternative embodiments. For example, the steps outlined above may beperformed in a different order. Moreover, the individual stepsillustrated in FIG. 11 may include multiple sub-steps that may beperformed in various sequences as appropriate to the individual step.Furthermore, additional steps may be added or removed depending on theparticular application. One of ordinary skill in the art would recognizemany variations, modifications, and alternatives.

Although specific embodiments of the present invention have beendescribed in detail, it will be apparent to one skilled in the art thatvarious changes and modification can be made therein without departingfrom the spirit and scope thereof.

1. A light emitting diode (LED) package comprising: a metal die padhaving a bottom planar surface, an upper surface, and a centrallylocated recessed cavity, the recessed cavity having a planar chip attachsurface between the bottom planar surface and the upper surface, therecessed cavity also having sidewalls that extend from the recessedplanar chip attach surface to the upper surface; first and second metalleads arranged on opposing sides of the die pad, the first and secondmetal leads having a bottom planar surface that is coextensive with thebottom planar surface of the die pad and an upper planar surface that iscoextensive with the upper surface of the die pad; an LED chip attachedto the chip attach surface within the recessed cavity, the LED chiphaving first and second bonding pads located on an upper surfacethereof; first and second conductors that electrically connect the firstand second bonding pads to the first and second metal leads,respectively; and a package body comprising an encapsulant, wherein theencapsulant fills a space between the metal die pad and the first andsecond metal leads and forms a bottom encapsulant surface that iscoextensive with the bottom planar surfaces of the die pad and thebottom planar surface of the first and second metal leads.
 2. The LEDpackage set forth in claim 1 wherein the sidewalls of the recessedcavity of the die pad form an obtuse angle at a junction where thesidewalls intersect the planar chip attach surface.
 3. The LED packageset forth in claim 2 wherein the sidewalls of the recessed cavity areplated with a metallic plating material to enhance the reflectiveproperties of the sidewalls.
 4. The LED package set forth in claim 1wherein the first and second leads have (i) an upper inner sidewallsurface facing the die pad that extends from the upper surface of theleads to a lower edge between the upper surface and bottom surfaces,(ii) a lower inner sidewall surface facing the die pad that intersectswith the bottom surface and (iii) an intermediate surface that extendsfrom the lower edge of the upper sidewall surface to the lower innersidewall surface, and wherein the encapsulant material covers the lowerinner sidewall surface of the first and second leads and at leastpartially covers the upper inner sidewall surface of the first andsecond leads.
 5. The LED package set forth in claim 1 further comprisingan insert that mates with the recessed cavity within the die pad tofunction as an LED light reflector, the insert having sidewalls thatextend from the planar chip attach surface of the recessed cavity to theupper surface and form an obtuse angle at the junction where thesidewalls intersect the recessed planar surface.
 6. The LED package setforth in claim 1 wherein the recessed cavity has either a rectangular orsquare shape.
 7. The LED package set forth in claim 1 wherein therecessed cavity has either a circular, hexagonal or octagonal shape. 8.The LED package set forth in claim 1 wherein the sidewalls of therecessed cavity have a glossy finish and function as an LED reflector.9. The LED package set forth in claim 1 wherein the sidewalls of therecessed cavity have a matte finish and function as an LED reflector.10. The LED package set forth in claim 1 further comprising: a pluralityof LED chips attached to the planar chip attach surface, each of the LEDchips having first and second bonding pads located on an upper surfaceof the chip; a plurality of sets of first and second metal leadsarranged on opposing sides of the metal die pad, one set of first andsecond leads for each of the LED chips in the plurality of chips; and aplurality of sets of first and second conductors, each set electricallyconnecting the first bonding pad of its respective LED chip to acorresponding first metal lead and electrically connecting the secondbonding pad of its respective LED chip to a corresponding second metallead.
 11. A leadframe for use in making light emitting diode (LED)packages, the leadframe comprising: a rectangular outer metal framehaving an upper planar surface and a lower planar surface; a pluralityof inner frames arranged in a matrix pattern within the outer metalframe, each of the inner frames comprising a chip containing area andfirst and second leads arranged on opposing sides of the chip containingarea; wherein the chip containing area and first and second leads have abottom surface coextensive with the lower planar surface and have anupper surface coextensive with the upper planar surface, the chipcontaining area further comprising a centrally located recessed cavityhaving a recessed planar surface between the upper and lower planarsurfaces of the leadframe and having sidewalls that extend from therecessed planar surface to the upper surface.
 12. The leadframe setforth in claim 11 wherein the sidewalls of the recessed cavity form anobtuse angle at the junction where the sidewalls intersect the recessedplanar surface.
 13. The leadframe set forth in claim 12 wherein thesidewalls of the recessed cavity are plated with a metallic platingmaterial to enhance the reflective properties of the sidewalls.
 14. Theleadframe set forth in claim 11 wherein the first and second leads have(i) an upper inner sidewall surface facing the chip containing area thatextends from the upper surface of the leads to a lower edge between theupper surface and bottom surfaces, (ii) a lower inner sidewall surfacefacing the chip containing area that intersects with the bottom surfaceand (iii) an intermediate surface that extends from the lower edge ofthe upper sidewall surface to the lower inner sidewall surface.
 15. Theleadframe set forth in claim 11 further comprising an insert that mateswith the recessed cavity within the chip containing area to function asan LED light reflector, the insert having sidewalls that extend from therecessed planar surface of the recessed cavity to the upper surface andform an obtuse angle at the junction where the sidewalls intersect therecessed planar surface.
 16. The leadframe set forth in claim 11 whereinthe recessed cavity has either a rectangular or square shape.
 17. Theleadframe set forth in claim 11 wherein the recessed cavity has either acircular, hexagonal or octagonal shape.
 18. The leadframe set forth inclaim 11 wherein the sidewalls of the recessed cavity have a glossyfinish and function as an LED reflector.
 19. The leadframe set forth inclaim 11 wherein the sidewalls of the recessed cavity have a mattefinish and function as an LED reflector.